1. Field of the Invention
This invention relates to a disc discrimination apparatus which may be provided in a recording-disc player such as an on-board CD (Compact Disc) player. In addition, this invention relates to a disc discrimination method.
2. Description of the Related Art
A conventional apparatus for reproducing recorded information from a recording disc such as a CD operates as follows. When a recording disc is inserted into an apparatus body, the conventional apparatus decides whether or not the inserted disc can be played by the apparatus, that is, whether or not recorded information can be reproduced from the inserted disc by the apparatus. In the case where the apparatus decides that the inserted disc can be played, the apparatus starts a process of reproducing recorded information from the disc. Otherwise, the apparatus does not start the process.
Japanese patent application publication number 2006-228401 discloses a disc discrimination process which includes a step of setting a focus gain, a step of provisionally setting a tracking gain, and a step of finally setting the tracking gain. In the disc discrimination process, a focus error amplitude related to an optical disc in question is repetitively measured to obtain a set of measured values. Then, the average of the measured values is calculated. In the disc discrimination process, a focus gain is set in response to the average focus error amplitude, and a decision is made as to whether the reflectivity of the optical disc in question is high or low on the basis of the set focus gain. Then, the optical disc with a high reflectivity is concluded to be a CD-DA. On the other hand, the optical disc with a low reflectivity is concluded to be a CD-RW.
In the disc discrimination process of Japanese application 2006-228401, a focus error amplitude is repetitively measured. The disc discrimination process includes a step of setting a focus gain, a step of provisionally setting a tracking gain, and a step of finally setting the tracking gain. Accordingly, it tends to take a long time to implement the disc discrimination process.